In many applications, such as audio upmixing, audio authoring and the like, an upmixing technique may be employed to create an immersive sound field. In such an application, multichannel audio signals may usually need to be decomposed into direct and/or diffuse signals.
As used herein, the term “direct signal” or “direct component” refers to an audio signal or component that gives an impression to a listener that a heard sound has an apparent direction. The term “diffuse signal” or “diffuse component” refers to an audio signal or component that gives an impression to a listener that the heard sound does not have an apparent direction or is emanating from a lot of directions around the listener. Typically, a direct signal may be a more dominant sound signal among multichannel audio signals, which is originated from a direct sound source and panned among channels. A diffuse signal may be a less dominant sound signal among the multichannel audio signals, which is weakly correlated with the direct sound source and/or distributed across channels, such as an ambiance sound, reverberation, etc. As used herein, the term “dominant signal” or “dominant component” refers to a signal or component having a larger power among a plurality of signals or components.
It is desirable to provide an approach to more precisely decompose the multichannel audio signals so as to provide a more immersive sound field.